Machine for assembling structures such as frames

ABSTRACT

A machine for the automatic production line assembly of a building structure such as a door frame having a pair of stiles and a pair of rails secured together in a rectangular configuration which includes a frame on which are mounted hoppers in which the tiles and rails are positioned in vertically stacked relationship, the lowermost rails and stiles in the hoppers being moved inwardly by fluid pressure actuated cylinder-piston assemblies and clamped thereby into an assembled condition for subsequent stapling together at the joints by staple guns mounted on the frame over the joints, the assembled structure being released by the clamping means for removal from the frame in a repetitive operation for the continuous production of such building structures.

[' Apr. 15, 1975 MACHINE FOR ASSEMBLING [57] ABSTRACT A machine for theautomatic production line assembly STRUCTURES SUCH AS FRAMES [76]Inventor: Marion 0. Fogle, Rt. 3, Box 377F,

Orangeburg, S.C. 291 15 Aug. 3, 1973 of a building structure such as adoor frame having a pair of stiles and a pair of rails secured togetherin a [22] Filed:

rectangular configuration which includes a frame on PP 335,431 which aremounted hoppers in which the tiles and rails are positioned invertically stacked relationship, the lowermost rails and stiles in thehoppers being moved inwardly by fluid pressure actuated cylinder-pistonassemblies and clamped thereby into an assembled condition forsubsequent stapling together at the joints by 0 RH mRo l lwo No 2 93ZMBD u 000 "00 m 22 m R R m 0 n O n 22 7 mm M mmmO 2 I n 9 m m h c n r ua u e u S III. I C s Umn Hum 555 staple guns mounted on the frame overthe joints, the assembled structure being released by the clamping meansfor removal from the frame in a repetitive oper- [56] References CitedUNITED STATES PATENTS ation for the continuous production of suchbuilding structures.

10 Claims, 4 Drawing Figures Primary ExaminerThomas H. Eager a PR".

PATENTEDAPR 1 5197s SHEET 1 [IF 2 PATENTEDAPR 1 1915 3; 877. 132 sumanfzMACHINE FOR ASSEMBLING STRUCTURES SUCH AS FRAMES This invention relatesto the building industry and move particularly to apparatus forconstructing a building component. Many structures in the buildingindustry utilize structural elements such as boards. panels. and thelike which are assembled into a wide variety of shapes and sizes to forman assembled structure which may be used alone or in combination withother similarly fabricated structures. The accuracy with which suchstructures are built must be within reasonable limits and therefore thestructural elements or component parts are generally assembled by handor by means of a jig and secured together by gluing staple. nails or thelike. Considerable time and labor is usually involved in the assembly ofsuch building structures and, with the rising costs of labor and theamount of labor required for such fabrication work, considerable efforthas been made to eliminate as much of the labor costs as possible by theuse of specially designed machinery for carrying out such fabricatingoperations. However, the wide variety of types of such buildingstructures do not economically justify special machinery for each typeof structure. In addition, many types of such building structures arenot suitable for mechanized assembly. An even greater factor to beconsidered is the tremendous cost and highly complex construction ofsuch machines considering the many individual operations which suchmachines would be required to perform even on the simplest of buildingstructures.

Accordingly, a primary object of this invention is to provide a new andnovel apparatus for the fabrication of building structures.

Another object of this invention is to provide a new and novel machinefor automatic assembly and fastening of structural elements into arectangular building structure.

A further object of this invention is to provide a new and novel machinefor the fabrication in a production line, repetitive type operation, abuilding structure which completely eliminates the need for manuallabor.

This invention further contemplates a provision of a new and novelmachine for fabricating a building structure such as a door frame or thelike which is simple and inexpensive in construction, which is capableof high speed operation for the fabrication of such structures at a highproduction rate, which is composed of a minimum of parts and which iscapable of prolonged use without breakdown.

A still further object of this invention is to provide a new and novelmachine for the automatic fabrication of a door frame of the typeutilized in hollow doors which is readily adjustable for fabricatingsuch frames in a wide variety of shapes and sizes and which not onlyautomatically feeds the frame components into the machine butautomatically removes structures assembled by the machine to a remotelocation.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings.

In general, the objects of this invention and other related objects areaccomplished by the provision of a substantially rectangular frameincluding a pair of side frame members arranged in spaced parallelrelationship and a pair of end'frame members arranged in spaced parallelrelationship to define a central opening. Means are provided on each ofthe side frame members for supporting a plurality of elongated sidestructural elements in a vertically stacked, storage position and meansare provided on each of the end frame members for supporting a pluralityof end structural elements in a vertically stacked, storage position.The supporting means on each of the frame members include clamping meansfor moving the side and end structural elements inwardly from thestorage position into an assembly psoition with adjacent portions of theelements in abutting engagement to form a building structure havingjoints. Fastening means are provided on the frame for securing theelements together at the joints to form an assembled building structure,the clamping means being arranged to release the assembled buildingstructure for removal of the structure from the frame.

The novel features which are believed to be characteristic of theinvention are set forth with particularity in the appended claims. Theinvention itself, however, both as to its organization and method ofoperation may be best understood by reference to the followingdescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a perspective view, partially broken away, of the apparatus ofthe invention;

FIG. 2 is perspective view of the building structure fabricated in theapparatus of FIG. 1;

FIG. 3 is a side elevation view of a portion of the apparatus of FIG. Iat one stage in the operation of the apparatus;

FIG. 4 is a view similar to FIG. 3 illustrating the parts in asubsequent stage in the operation of the invention.

Referring now to the drawings, there is shown on FIG. 1 a machineconstructed in accordance with the invention which is used forfabricating building structures such as a door frame designatedgenerally in FIG. 2 by the letter D. It should be understood thatalthough the apparatus of the invention will be described hereinafterfor use in the fabrication of such frames D, any building structure ofthe type corresponding to the frame D may be produced with the machineof invention.

The door frame D is of the well known construction which is used as aninner frame or skeleton for what is referred to as a hollow door. Theframe D includes a pair of end structural elements such as rails ll, 12,generally formed of wood or the like, and arranged in spaced parallelrelationship. The frame D also includes a pair of side structuralelements such as stiles l3, 14, also formed from wood or the like. Inthe illustrated embodiment, rails 11, 12, and stiles 13, 14, arefastened together by suitable means such as staples 16 although itshould be understood that any suitable type of fastening means may beused such as hot melt adhesive or the like.

In the formation of a door using frame D, the interior of the frame isfilled with reinforcing material such as a honeycomb insert and theframe is enclosed by a skin such as plywood panels on both faces to forma hollow door. In one hollow door construction, a lock block is utilizedsuch as the lock block 17 shown in FIG. 2, the lock block 17 beingformed from wood or the like and secured to one of the side structuralelements such as stile 13 by means such as staples 18.

Referring now again to FIG. 1, the apparatus of the invention includes apair of side frame members 21, 22 arranged in spaced parallelrelationship and a pair of end frame members 23, 24 similarly arrangedin spaced parallel relationship and secured to the side frame members21, 22 by welding or the like. The .side frame members 21, 22 and endframe members 23, 24 form a frame of substantially rectangularconfiguration designated generally in FIG. 1 by the letter F. A conveyor30 driven by suitable means (not shown) in the direction of the arrow Iis disposed below the frame central opening 26 for a purpose to beexplained hereinafter.

Means are provided on each of the side frame members 21, 22 forsupporting at least one of the side structural elements or stiles 13, 14in a storage position. Most specifically, the supporting means include ahopper on each of the side frame members 21, 22 designated generally bythe numerals 27, 28 respectively. The hoppers 27, 28 are substantiallyidentical in construction and hopper 27 includes a pair of upstandingchannel members 29, 31 arranged in spaced relationship and suitablysecured by welding or the like to the frame F adjacent the corners ofthe frame as shown best in FIG. 1. Preferably, the channel members 29,31 are provided with reinforcing members 32, 33 secured by welding orthe like to opposite sides of the channel members 29, 31 and the hopper27 is arranged to accommodate in vertically stacked relationship, aplurality of stiles 13.

Similarly a pair of channel members 36, 3 7 are suitably mounted on theframe F adjacent the corners of the frame on the side defined by theside frame member 22. The channel members 36, 37 define there betweenthe hopper 28 for accommodating a plurality of side structural elementsor stiles 14in a vertically stacked, storage position. The channelmembers 36, 37 are similarly reinforced by cross members 38, 39 securedby suitable means such as welding or the like to the opposite sides ofthe channel members 36, 37.

Means are provided on each of the end frame members for supporting atleast one end structural element such as the rails 11, 12 in a storageposition. Most specifically, a pair of upstanding frame members 41, 42are secured in laterally spaced relationship to the end frame member 23together with upstanding frame members 43, 44 arranged in spacedparallel relationship with frame members 41, 42 respectively fordefining a hopper 46 for accommodating at least one and preferably aplurality of end structural elements or rails 12 in the verticallystacked relationship as shown. Preferably, reinforcing member 47 issuitably secured to the frame members 41, 42 and additional support forthe frame members 43, 44 is provided with L-shaped brackets 48, 49suitably secured by welding or the like to the frame members 43, 44 andchannel members 29, 36 respectively. 1 Similarly, a pair of upstandingframe members 51, 52 arranged in laterally spaced relationship aresecured to the end frame member 24 together with upstanding framemembers 53, 54 arranged in spaced parallel relationship with the framemembers 51, 52 to define a hopper, designated generally by the numeral56, for accommodating at least one and preferably a plurality of endstructural elements such as rails 11 in a vertically stackedrelationship as shown. Preferably, the frame members 51, 52 are providedwith reinforcing member 57 and L-shaped brackets 58, 59 suitably securedto the frame members 53, 54 and to channel members 31, 37 respectivelyfor supplemental of the hopper 56.

The supporting means for supporting the stiles l3, l4 and rails 11, 12also include clamping means for moving the stiles and rails from thestorage position of FIG. 1 into an assembly position with adjacentportions of the elements in abutting engagement to form a buildingstructure such as the frame D. Most specifically, as shown best in FIG.I, each of the hoppers 27, 28, 46, 56 has operatively associatedtherewith a fluid pressure operated, cylinder-piston assembly designatedgenerally by the numeral 61. Each of the cylinder-piston assembliesincludes a cylinder 62 and a piston 63 and is connected to an associatedsource of fluid pressure through a suitable control valve (not shown) inthe conventional manner.

Each cylinder-piston assembly 61 is preferably secured to a base plate64 which is mounted on the associated side and end frame members 21-24and on the frame F as shown by the frame portions designated generallyby the numeral 66.

It should be understood that each cylinder-piston assembly 61 issubstantially identical in construction and therefore like numerals willbe used hereinafter to identify like parts.

Referring now specifically to FIGS. 3, 4, an L-shaped support plate,designated generally by the numeral 67, is secured to the outer end 63aof each of the pistons 63. The support plate 67 includes a horizontallyextending plate portion 67a and a vertically extending leg portion 67bsecured to the piston outer end 63a. It will be noted that, in thepreferred embodiment the support plate 67 is thus positioned on thepiston 63 below the upper surface 63b of the piston for a purpose to beexplained hereinafter.

As is well know, the piston 63 is movable between the retracted positionof FIG. 3 and the extended position of FIG. 4. In the retracted positionof FIG. 3, the support plate is positioned beneath the associated hoppersuch as the hopper 27 of FIG. 3. Thus, the lowermost stile 13 of thevertically stacked stiles 13 in the hopper 27 is supported on thesupport plate 67 in the retracted position of the piston 63 and all ofthe pistons 63 are initially in the retracted position with thelowermost rails and stiles in the storage position prior to theoperation of the apparatus of FIG. 1.

Although it should be understood that a door frame D of a type formedfrom stiles 13, 14 and rails 11, 12 only may be formed in the apparatusof the invention, in the illustrated embodiment, an auxiliary hopper 68is provided for the type of door frame shown in FIG. 2 utilizing a lockblock 17. The hopper 68 is preferably formed with a pair of channelmembers 71, 72 supported on the Frame F in spaced relationship as shownin FIG. 1 to provide auxiliary supporting means on the frame forsupporting at least one intermediate structural element such as the lockblock 17 in a storage position. The auxiliary hopper 68 is supported onthe frame F adjacent thestructural elements supported on one of the sideframe members such as the stiles 13 supported in the hopper 27 on theside frame member 21 as shown best in FIG. 3. A freely pivotal,downwardly depending flap member 70 is mounted on the lower end of thehopper 68 adjacent the hopper 27 for a purpose to be explainedhereinafter. The auxiliary supporting means for the lock block 17 alsoincludes the clamping means associated with the side frame member 21which includes the support plate 67 on which the lowermost lock block17' in the stack of lock blocks 17 is supported asshown in FIG. 3.

The frame F also includes top means adjacent each of the end framemembers 11, 12 for limiting the movement of the railsll, 12 to anassembly position within the interior of the frame F over the centralopening 26. More specifically, a framework designated generally by thenumeral 73 is suitably supported on the frame F, preferably on theupstanding frame members 53, 54 as shown adjacent the end frame member24. The framework 73 includes downwardly depending spaced-apart legs 74,76 which are arranged to be engaged by the rail 11 as will be explainedhereinafter. Similarly, a framework 77 is supported on the frame Fadjacent the end frame member 23 preferably on the upstanding framemember 43, 44 and includes a pair of downwardly pending leg portions 78,79 for engagement by the rail 12 in the assembly position.

The apparatus of the invention includes fastening means on the frame Ffor securing the structural elements together to form an assembledbuilding structure. Most specifically, in the assembled condition of theelements such as rails 11, 12 and stiles 13, 14, D joints, designatedgenerally by the letter J, are formed by the elements where portions ofthe elements abutt. In the embodiment of FIG. 2, lock block 17 alsoforms a joint designated generally by the letter J with the stile 13.

Although, a hot melt adhesive or the like may be utilized, in thepreferred embodiment staple guns of conventional construction eachhaving a stapling head H are utilized to fasten the elements together.As shown best in FIG. "1, the staple guns are preferably of thepneumatic type are automatically actuated by suitable control means (notshown). The staple guns S are supported on the frame F with the staplegun head H in overlying relationship with the joints J and J in theassembly position of the elements. It will be noted that preferably apair of staple guns S are utilized for the lock block 17.

As shown best in FIGS. 3, 4, each of the staple guns S is provided witha laterally extending spring plate 81 suitably secured to the staple gunhead H the spring plates 81 being arranged for overlying slidingengagement with the adjacent structural element during the movement ofthe structural element from the storage position into the assemblyposition. By means of the spring plates 81, the structural element suchas rails 11, 12 and stiles 13, 14 are yieldingly guided and retainedbetween the L-shaped plate number 67 and the spring plate 81 thusretaining the structural elements in the proper stapling position underthe head H. ln order to retain the intermediate structural element orlock block 17 in the assembly position, a framework 82 having downwardlydepending leg members 83 is suitably secured to the channel member 71,72 of the hopper 68 the members 83 engaging the lock block 17 andlimiting the movement of the lock block to the assembly position as itis moved from the storage position.

In the operation of the invention, rails 11, 12 are stacked in thehoppers 56, 46 respectively, stiles 13, 14 are stacked in the hoppers27, 28 respectively and lock blocks 17 are stacked in the hopper 68 thelowermost structural element in each of the hoppers resting on thesupport plate 67 with the piston 63 of the assemblies 61 in theretracted position as shown in FIG. 3. It should be understood that FIG.3 shows the cylinder-piston assembly associated with hoppers 27, 68 andthat the other hoppers and cylinder-piston assemblies are similarlyarranged.

By automatic actuation through suitable valve control means (not shown),the cylinder-piston assemblies 61 associated with hoppers 46, 56 areactuated to move the pistons 63 fromthe retracted position to theextended position in the manner shown in FIG. 4 to move the rails 11, 12respectively against the stop members 74, 76 and 78, 79 respectivelyinwardly of the frame F into an assembly position over the centralopening 26. Subsequently, the cylinder-piston assemblies 61 associatedwith hoppers 27, 28 are actuated to move the stiles l3, l4 inwardly sothat the end portions of the stiles l3, l4 engage the ends of the rails11, 12 to formthejoints J the subsequent structural elements in thehoppers dropping down onto the pistons 63 for a portion of its totaldrop as shown on FIG. 4. During the movement of the stile l3 inwardlyinto the assembly position, the lowermost lock block 17 is also movedahead of the lowermost stile 13, the flap member 70 pivoting upwardly toretain the subsequent lock block 17" within the hopper 68. The movementof the lowermost lock block 17' and consequently the lowermost stile 13is limited to the assembly position by the engagement with the stopmembers 83.

At this time all of the staple guns S are actuated injecting the staples16, 18 into the respective joints J, J, forming the assembled buildingstructure or door frame D. All of the pistons 63 are then retracted bysuitable actuation of the cylinder-piston assemblies 61 so that theframe D falls downwardly through the central opening 26 in the frame Fonto the conveyor 30 moving in the direction of the arrow l to conveythe "assembled frame D to a remote location. 1 i

As the pistons 63 return to the retracted position of FIG. 3, thesubsequent rails, stiles and lock blocks drop onto the respectivesupport plates 67 and the apparatus of the invention is ready foranother assembly opera- 1 tion.

It should be understood that the apparatus of the invention may be madeadjustable in many respects for fabricating various sizes and types ofbuilding structures. For instance, the hoppers 27, 28, 46, 56 and 68 maybe provided with adjustable components so as to accommodate varioussizes of stiles, rails and lock blocks. The frame F may itself beconstructed for adjustably positioning the frame members 21-24 for thefabrication of various sizes and shapes of building structures such asdoor frame D. It is also desirable to mount the cylinder-pistonassemblies 61 for adjustable positioning so as to calibrate the strokesof the pistons and insure the application of the optimum amount ofretaining force exerted on the structural elements by the pistons in theassembly position.

While there has been described what at present is considered to be thepreferred embodiment of the invention, it will be understood by thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention.

Having thus described the invention, what is claimed 1. Apparatus forfabricating building structures of the type having a pair of endstructural elements and a pair of side structural elements comprising incombination, a substantially rectangular frame. including a pair of sideframe members arranged in spaced parallel relationship and a pair of endframe members arranged in spaced parallel relationship means on each ofsaid frame members for supporting at least one of said side structuralelements in a storage position, means on each of said end frame membersfor supporting at least one of said end structural elements in a storageposition, said supporting means including clamping means for moving saidside and end structural elements from said storage position into anassembly position with adjacent positions of said elements in abuttingengagement to form a building structure having joints, fastening meanson said frame for securing said elements together at said joints to forman assembled building structure, said clamping means being arranged torelease said assembled building structure for removal of said structurefrom said frame.

2. Apparatus for fabricating building structures in accordance withclaim 1 including auxiliary supporting means on said frame forsupporting at least one intermediate structural element in a storageposition adjacent one side structural element supported on one of saidside frame members, said clamping means associated with said one sideframe member being arranged to move said intermediate structural elementfrom said storage position into an assembly position together with saidone side structural element and fastening means on said frame forsecuring said intermediate structural element and said one sidestructural element together in said assembled structure.

3. Apparatus for fabricating building structures in accordance withclaim 2 wherein said auxiliary supporting means include an upstandingauxiliary hopper supported on said frame in aligned relationship withsaid supporting means on said one side frame member, said auxiliaryhopper being arranged to support a plurality of said intermediatestructural elements in vertically stacked relationship, a freelypivotal, downwardly suspended flap member on the lower end of saidauxiliary hopper adjacent said one side frame member supporting meansfor upward pivotal movement into temporary supporting engagement withthe subsequent intermediate structural element in said auxiliary hopperduring the movement of the lowermost structural element in said one sideframe member supporting means from said storage position into saidassembly position and for downward pivotal movement for release of saidsubsequent structural element during the release of said assembledbuilding structure by said clamping means and auxiliary stop means onsaid frame for limiting the movement of said intermediate structuralelement to said assembly position.

4. Apparatus for fabricating building structures in accordance withclaim 1 wherein said supporting means includes an upstanding hopper oneach of said side and end frame members, each of said hoppers beingarranged to support a plurality of said structural elements invertically stacked relationship and wherein said clamping means on eachof side and end frame members is arranged to successively move thelowermost structural element in said hoppers from said storage positioninto said assembly position.

5. Apparatus for fabricating building structures in accordance withclaim 4 including stop means on said frame adjacent each of said endframe members for limiting the movement of said end'structural elementsto said assembly position and wherein said clamping means on said sideframe members if arranged to move said side structural elements intosaid assembly position subsequent to the positioning of said endstructural elements in said assembly position to thereby permit said endstructural elements to limit the movement of said side structuralelements to said assembly position.

6. Apparatus for fabricating building structures in accordance withclaim 5 wherein said side and end frame members define a central openingand including conveyor means disposed in underlying relationship withsaid frame and in alignment with said central opening, said centralopening being arranged to permit said assembled building structure tomove from said assembly position downwardly through said opening ontosaid conveyor means upon release by said clamping means.

7. Apparatus for fabricating building structures in accordance withclaim 6 wherein said clamping means include a fluid pressure operatedcylinder-piston assembly positioned on said frame adjacent each of saidhoppers, an L-shaped support plate secured to the outer end of thepiston of each of said cylinder-piston assemblies, each of said pistonsbeing movable into a retracted position with said support plate inunderlying relationship with the associated hopper to supportinglyreceive the lowermost structural element in said associated hoppercorresponding to said storage position and into an extended positioncorresponding to said assembly position for forming said structuralelements into said assembled building structure, each of said pistonsbeing movable from said extended position to said retracted position torelease said assembled building structure and permit said support plateto receive the subsequent structural element in said associated hopper.

8. Apparatus for fabricating building structures in accordance withclaim 7 wherein said fastening means comprises a plurality of stapleguns having a stapling head supported on said frame, each of said stapleguns being disposed on said frame with said stapling head in overlying,operative relationship with one of said joints in said assembledbuilding structure for stapling said structural elements together atsaid joint.

9. Apparatus for fabricating building structures in accordance withclaim 8 including a laterally extending spring plate on each of saidstaple gun heads for overlying, sliding engagement with the adjacentstructural element during the movement of said structural elements intosaid assembly position to yieldingly guide said structural element intounderlying relationship with said head.

10. Apparatus for fabricating building structures in accordance withclaim 9 wherein said L-shaped support plate includes a horizontalextending plate portion and a vertically extending leg portion having anupper end secured to said piston outer end to permit said piston tosupport said subsequent structural element during the movement of saidlowermost structural element from said storage to said assembly positionand to limit the downward movement of said subsequent structural elementonto said support plate during the movement of said piston from saidextended to said retracted position and including a spring disposed inencircling relationship with said piston between said cylinder and saidsupport plate for yieldingly urging said structural elements together insaid assembly position.

1. Apparatus for fabricating building structures of the type having apair of end structural elements and a pair of side structural elementscomprising in combination, a substantially rectangular frame including apair of side frame members arranged in spaced parallel relationship anda pair of end frame members arranged in spaced parallel relationshipmeans on each of said frame members for supporting at least one of saidside structural elements in a storage position, means on each of saidend frame members for supporting at least one of said end structuralelements in a storage position, said supporting means including clampingmeans for moving said side and end structural elements from said storageposition into an assembly position with adjacent positions of saidelements in abutting engagement to form a building structure havingjoints, fastening means on said frame for securing said elementstogether at said joints to form an assembled building structure, saidclamping means being arranged to release said assembled buildingstructure for removal of said structure from said frame.
 2. Apparatusfor fabricating building structures in accordance with claim 1 includingauxiliary supporting means on said frame for supporting at least oneintermediate structural element in a storage position adjacent one sidestructural element supported on one of said side frame members, saidclamping means associated with said one side frame member being arrangedto move said intermediate structural element from said storage positioninto an assembly position together with said one side structural elementand fastening means on said frame for securing said intermediatestructural element and said one side structural element together in saidassembled structure.
 3. Apparatus for fabricating building structures inaccordance with claim 2 wherein said auxiliary supporting means includean upstanding auxiliary hopper supported on said frame in alignedrelationship with said supporting means on said one side frame member,said auxiliary hopper being arranged to support a plurality of saidintermediate structural elements in vertically stacked relationship, afreely pivotal, downwardly suspended flap member on the lower end ofsaid auxiliary hopper adjacent said one side frame member supportingmeans for upward pivotal movement into temporary supporting engagementwith the subsequent intermediate structural element in said auxiliaryhopper during The movement of the lowermost structural element in saidone side frame member supporting means from said storage position intosaid assembly position and for downward pivotal movement for release ofsaid subsequent structural element during the release of said assembledbuilding structure by said clamping means and auxiliary stop means onsaid frame for limiting the movement of said intermediate structuralelement to said assembly position.
 4. Apparatus for fabricating buildingstructures in accordance with claim 1 wherein said supporting meansincludes an upstanding hopper on each of said side and end framemembers, each of said hoppers being arranged to support a plurality ofsaid structural elements in vertically stacked relationship and whereinsaid clamping means on each of side and end frame members is arranged tosuccessively move the lowermost structural element in said hoppers fromsaid storage position into said assembly position.
 5. Apparatus forfabricating building structures in accordance with claim 4 includingstop means on said frame adjacent each of said end frame members forlimiting the movement of said end structural elements to said assemblyposition and wherein said clamping means on said side frame members ifarranged to move said side structural elements into said assemblyposition subsequent to the positioning of said end structural elementsin said assembly position to thereby permit said end structural elementsto limit the movement of said side structural elements to said assemblyposition.
 6. Apparatus for fabricating building structures in accordancewith claim 5 wherein said side and end frame members define a centralopening and including conveyor means disposed in underlying relationshipwith said frame and in alignment with said central opening, said centralopening being arranged to permit said assembled building structure tomove from said assembly position downwardly through said opening ontosaid conveyor means upon release by said clamping means.
 7. Apparatusfor fabricating building structures in accordance with claim 6 whereinsaid clamping means include a fluid pressure operated cylinder-pistonassembly positioned on said frame adjacent each of said hoppers, anL-shaped support plate secured to the outer end of the piston of each ofsaid cylinder-piston assemblies, each of said pistons being movable intoa retracted position with said support plate in underlying relationshipwith the associated hopper to supportingly receive the lowermoststructural element in said associated hopper corresponding to saidstorage position and into an extended position corresponding to saidassembly position for forming said structural elements into saidassembled building structure, each of said pistons being movable fromsaid extended position to said retracted position to release saidassembled building structure and permit said support plate to receivethe subsequent structural element in said associated hopper. 8.Apparatus for fabricating building structures in accordance with claim 7wherein said fastening means comprises a plurality of staple guns havinga stapling head supported on said frame, each of said staple guns beingdisposed on said frame with said stapling head in overlying, operativerelationship with one of said joints in said assembled buildingstructure for stapling said structural elements together at said joint.9. Apparatus for fabricating building structures in accordance withclaim 8 including a laterally extending spring plate on each of saidstaple gun heads for overlying, sliding engagement with the adjacentstructural element during the movement of said structural elements intosaid assembly position to yieldingly guide said structural element intounderlying relationship with said head.
 10. Apparatus for fabricatingbuilding structures in accordance with claim 9 wherein said L-shapedsupport plate includes a horizontal extending plate portion and avertically extending leg portion having an upper end sEcured to saidpiston outer end to permit said piston to support said subsequentstructural element during the movement of said lowermost structuralelement from said storage to said assembly position and to limit thedownward movement of said subsequent structural element onto saidsupport plate during the movement of said piston from said extended tosaid retracted position and including a spring disposed in encirclingrelationship with said piston between said cylinder and said supportplate for yieldingly urging said structural elements together in saidassembly position.